190 research outputs found

    Simulation of Cognitive Electronic Warfare System With Sine and Square Waves

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    Today’s Electronic Warfare (EW) receivers need advanced technology to achieve real-time surveillance operations. Dynamic and intelligent systems are required for UAVs and other airborne applications. The airborne Electronic Warfare systems must be knowledge-based systems, learning from the threat scenario with highly integrated capabilities to detect, react, and adapt to radar threats in real-time. Artificial intelligence is a machine-dependent process, by adapting certain rules and logic supported by human intelligence, AI can be used for cognitive processing. Cognitive signal processing is required for making the system autonomous and dynamic in nature. Military action on radar signatures requires a set of commands to be executed dynamically with the help of the proposed EW system. It is proposed to design and develop a cognitive EW architecture and simulation of machine learning that combines neural network architecture with the help of sine and square waves as input. This paper presents the Cognitive signal processing for EW systems with Neural Network, Recurrent Neural Network (RNN), Machine learning (ML), and Deep learning (DL) techniques with their simulation with sine and square waves

    Modelling and Simulation of IDMA-OFDM for Underwater Acoustic Communication

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    The Ocean exhibits phenomenon of changing acoustic signal transmission due to its non-stationary nature. Water columns in between transmitter and receiver are not fixed at any point of time. Thus, designing of a wireless communication systems for underwater applications becomes significantly challenging. The speed of sound in water is 1500 m/s which introduces large delay spread in acoustic signal due to multipath phenomenon. The large time delay causes Inter-symbol Interference; this ISI degrades the performance of many receivers. However orthogonal frequency division multiplexing is multi-tone modulation reduces long time delay spreads of acoustic channels. The interleave division multiple access distinguishes each user with the unique random interleaver code. The IDMA-OFDM is superior design for reducing error bursts in multi-access underwater applications. A Simulink based simulation modell of IDMA-OFDM system has been discussed in this paper. Satisfactory performance of the implementation was observed through analysis of BER with respect to SNR. The results have been concluded by comparing simulated data in BER tool of Simulink.Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 307-311, DOI: http://dx.doi.org/10.14429/dsj.65.860

    Radar Signal Recovery using Compressive Sampling Matching Pursuit Algorithm

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    In this study, we propose compressive sampling matching pursuit (CoSaMP) algorithm for sub-Nyquist based electronic warfare (EW) receiver system. In compressed sensing (CS) theory time-frequency plane localisation and discretisation into a NĂ—N grid in union of subspaces is established. The train of radar signals are sparse in time and frequency can be under sampled with almost no information loss. The CS theory may be applied to EW digital receivers to reduce sampling rate of analog to digital converter; to improve radar parameter resolution and increase input bandwidth. Simulated an efficient approach for radar signal recovery by CoSaMP algorithm by using a set of various sample and different sparsity level with various radar signals. This approach allows a scalable and flexible recovery process. The method has been satisfied with data in a wide frequency range up to 40 GHz. The simulation shows the feasibility of our method

    Discrete Electronic Warfare Signal Processing using Compressed Sensing Based on Random Modulator Pre-Integrator

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    Electronic warfare receiver works in the wide electromagnetic spectrum in dense radar signal environment. Current trends in radar systems are ultra wideband and low probability of intercept radar technology. Detection of signals from various radar stations is a concern. Performance and probability of intercept are mainly dependent on high speed ADC technology. The sampling and reconstruction functions have to be optimized to capture incoming signals at the receiver to extract characteristics of the radar signal. The compressive sampling of the input signal with orthonormal base vectors, projecting the basis in the union of subspaces and recovery through convex optimisation techniques is the current traditional approach. Modern trends in signal processing suggest the random modulator pre-integrator (RMPI), which sample the input signal at information rate non-adaptively and recovery by the processing of discrete and finite vectors. Analysis of RMPI theory, application to EW receiver, simulation and recovery of EW receiver signals are discussed

    Assessment of safety and efficacy of a dietary supplement KaraLiv™ in supporting liver health: a double-blind, parallel, placebo-controlled randomized clinical trial

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    Background: The liver is responsible for many critical functions within the body. If the liver becomes diseased or injured, loss of those critical functions can cause significant damage to the body. KaraLivTM is a novel herbal formulation which contains a blend of different herbal extract ingredients. The current study tested the safety and efficacy of KaraLivTM versus a placebo control in supporting liver function.Methods: The study is a randomized, double-blind, parallel, and placebo-controlled study. A total of 60 patients were divided into 2 groups of 30 each. One group was given KaraLivTM and the other group was given a placebo for a period of 56 days. Treatment results were assessed by evaluating the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and alkaline phosphatase (ALP) in both groups.Results: The herbal supplement KaraLivTM significantly supported healthy liver function compared to the placebo following the 56 days of treatment. The treatment (KaraLivTM) group showed a statistically significant improvement in assessed liver enzyme levels compared to the placebo group.Conclusions: The all-natural herbal supplement KaraLivTM is a safe and effective product that can significantly help support healthy liver function

    Vascular injuries associated with total knee arthroplasty

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    Iatrogenic vascular injuries are rare but potentially devastating complications of total knee arthroplasty (TKA). This retrospective study analyzes vascular injuries associated with total knee arthroplasties in an urban, tertiary level referral hospital between 01 April 2010 to 31 March 2020 consisting of 6548 TKAs. Six patients sustained vascular injuries which included five primary, and one revision TKAs. Three patients were bilateral, and two were unilateral primary TKAs. The mean age-adjusted Charlson’s comorbidity index was two (range 1-3). Only two injuries were recognized intraoperatively. They underwent successful vascular repair. The third patient was diagnosed and underwent a vascular repair on the first postoperative day but experienced a permanent foot drop. Two other patients underwent thrombectomy on the fifth postoperative day; one required above-knee amputation, and the other continued to suffer from vascular claudication and paraesthesia. Another patient developed a pseudoaneurysm, which was identified and repaired five months after the primary TKA. The site of vascular injury was popliteal artery in five and superficial femoral artery in one patient. The mechanism of injury was a direct laceration in three, posterior Hohman's retractor in one, the effect of tourniquet on calcified vessels in one, and unknown in one patient. Early recognition was the only factor that significantly altered the functional outcome and limb salvage. Bilateral simultaneous total knee arthroplasties had no higher risks. A mandatory institutional protocol to recognize the early signs of vascular injuries is necessary for successful vascular repair

    Multi GNSS IRNSS L5 IRNSS S1 and GPS L1 Hybrid Simulator A Reconfigurable Low cost Solution for Research and Defence Applications

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    Satellite-based positioning field of research is growing rapidly as there is an increase in demand for precise position requirements in various civil and commercial applications. There are many errors that affect the GNSS signals while propagation from satellite to receiver, which eventually induces errors in pseudo-range measurements. In order to assess the receiver characteristics for a specific error condition, the real-time signals may not be appropriate, and it is challenging to perform repeated experiments with the same error condition. The advantage of the GNSS simulator is that users can model the different scenarios for any given location on the globe, which are repeatable at any point of time. The conventional hardware simulators are expensive and have few limitations. In this paper, a reconfigurable hybrid simulator is proposed with some advantages over traditional hardware simulators, such as low cost, reconfigurability, and controllability over fundamental parameters. It can be able to record intermediate stage data, which makes it more suitable for the GNSS research field. The proposed multi-GNSS simulator considered implementing IRNSS-L5, IRNSS-S1, and GPS-L1 band signals. A general-purpose computer can perform the necessary calculations for signal generation. The hybrid simulator can be able to generate the digital I/Q data, which can be stored as I/Q data or can be connected to a general-purpose SDR (Software Defined Radio) for RF signal generation (bladeRF in this case). The I/Q data can be used with the software receiver to analyse the receiver performance concerning the specific error. The generated GNSS signals are validated with software and hardware receivers, and the obtained position is observed as expected.&nbsp

    Novel Mannich bases bearing pyrazolone moiety. Synthesis, characterization and electrochemical studies

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    The present investigation describes a series of new {4-[3-Methyl-5-oxo-4-(4|-substituted phenyl hydrazono)-4,5-dihydro-pyrazol-1-yl]-phenoxy}-acetic acid (2-oxo-1-piperidine-1-ylmethyl-1,2-dihydro–indol-3-ylidene)-hydrazides synthesized by the Mannich reaction of {4-[3-Methyl-5-oxo-4-(4|-substituted phenyl hydrazono)-4,5-dihydro-pyrazol-1-yl]-phenoxy}-acetic acid (2-oxo-1,2-dihydro-indol-3-ylidene)-hydrazide with aqueous formaldehyde and a solution of piperidine in dimethylformamide. These novel Mannich bases were characterized by elemental analysis, IR, 1H NMR and mass spectral data. Electrochemical behavior of these compounds were studied by two techniques namely polarography and cyclic voltammetry. The results from both the techniques were compared and the reduction mechanism in acidic as well as basic medium was proposed

    Investigations on prevalence of aflatoxin contamination in major groundnut growing states of India, influence of soil characteristics and farmers’ level of awareness

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    Food safety issues are of major concern in groundnut due to aflatoxin contamination by Aspergillus flavus. Monitoring aflatoxin prevalence and understanding the factors responsible can provide useful information for devising effective management strategies. The present study focused on mapping the pre-harvest aflatoxin contamination in India along with its determining factors. A comprehensive survey was undertaken during 2012-2014 in four major groundnut growing States such as Andhra Pradesh, Gujarat, Karnataka, and Tamil Nadu. Pod (n=2434) and rhizospheric soil samples (n=1322) were collected to ascertain A. flavus populations and pre-harvest aflatoxin contamination. Further, kernel aflatoxin levels were correlated with soil organic carbon, available calcium and pH levels in the fields from where the samples were collected. Farmers’ awareness on aflatoxin problem was also determined using a semi-structured questionnaire. Our results indicate wide variations in the occurrence of pre-harvest aflatoxin contamination levels of kernels among different States (0 - 5486 ppb) and samples within States. Detectable levels of aflatoxins (>1ppb) were highest in Karnataka (70.5%), whereas it was lowest in Andhra Pradesh (32.9%). Correlation studies revealed that aflatoxin contents were positively associated with soil pH (r = 0.54-0.99) and A. flavus populations (r = 0.63 in Gujarat; r = 0.75 in Karnataka) whereas soil organic carbon and available calcium were negatively correlated with toxin levels in kernels (r = -0.99). Farmers’ awareness was considerably poor in all the States under survey. Overall, our results suggest the prevalence of aflatoxin contamination in major groundnut growing areas in India, and influence of certain edaphic factors
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